The phones, the Droid Mini, Droid Ultra and Droid Maxx will go on sale for $99, $199 and $299 for customers who sign a two year contract and will be available in Verizon stores August 20, according to Verizon Wireless.

The latest Droid line-up marks the first phone range that Motorola has designed since it was bought by Google in 2012. It will be followed in little over a week by the August 1 unveiling of the Moto X, a hotly anticipated smartphone from Motorola.

Verizon Wireless and Motorola launched the first phones under the Droid brand for phones based on Google Android software in 2009, at a time when rival AT&T Inc still had exclusive rights to sell the Apple Inc iPhone.

The Droid brand helped to resuscitate a struggling Motorola at the time as Verizon Wireless supported the device with a massive marketing campaign.

The exclusivity agreement with Motorola could be a blow for phone makers including HTC Corp, whose devices have also carried the Droid brand in the past as have devices from Korea's Samsung Electronics.

Verizon Wireless Vice President of Marketing Jeff Dietel said that since Droid phones should only include its "elite" phones based on Google's Android software it wanted a manufacturer "that matched all the expectations" for unique hardware and services.

Dietel said that his company would still carry Android phones from vendors besides Motorola.

Rick Osterloh, Motorola's senior vice president of product management, declined to comment on how the upcoming Moto X phone will differ from Droid phones and who will sell that device.

The lowest price Droid phone the Mini is a compact device with a 4.3 inch display. Motorola boasted that its mid-priced phone in the range, the Ultra, is the skinniest smartphone that can run on high-speed Long-Term Evolution (LTE) networks.

It claimed that its Maxx phone has the best battery life of any LTE phone on the market. It can be used for as long as 48 hours without being charged, compared with a previous version of the device which boasted 32 hours of battery life.

Verizon said the full retail price would be $499 for the Mini, $599 for the Ultra and $699 for the Maxx.

Verizon Wireless is a venture of Verizon Communications and Vodafone Group Plc.